Illustration of cytokine storm
Key Points:
- Researchers may have identified a new biomarker for severe COVID-19.
- Patients with acute COVID-19 infections were found to have increased levels of the cytokine interleukin-26 (IL-26) in their blood.
- The discovery may have also identified a new therapeutic target.
Researchers at Karolinska Institutet in Sweden have shown patients with acute COVID-19 infection have increased levels of the cytokine interleukin-26 (IL-26) in their blood. Additionally, researchers discovered that high IL-26 levels correlate with an exaggerated inflammatory response that signifies severe cases of the disease.
The researchers tried, for the first time, to ascertain whether immune signaling via IL-26 is involved in severe COVID-19.
“We already know that IL-26 is engaged in mobilizing immune cells that combat bacterial infections in the lungs and also in chronic respiratory disease in humans,” said the study’s last author Anders Lindén, professor at Karolinska Institutet. “What’s more, IL-26 has antiviral and antibacterial effects.”
To study how the molecule is involved in COVID-19, the scientists recruited 49 patients who had been hospitalized with SARS-CoV-2-infection, 44 of whom had severe symptoms and needed oxygen therapy. The patients were recruited at a hospital in Stockholm from June 2020 to January 2021. A control group of 27 healthy individuals was also recruited during the same period. The researchers then measured levels of IL-26 protein and other inflammatory compounds in the blood.
According to the study results, published in Frontiers in Immunology, blood levels of IL-26 were much higher in patients with COVID-19 than in the healthy controls. The researchers noted that the increase was associated with the so-called cytokine storm—an excessive and dangerous inflammatory response that signifies severe cases of COVID-19.
“Our discovery gives us a potential biomarker for severe COVID-19, but given the antiviral effects of IL-26, we may also have identified a new therapeutic target,” said Lindén.
Given the promising results, the research team says they will now conduct another study using a larger patient cohort.
Information provided by Karolinska Institutet.